The average weight of 50 teachers is 46kg. If the average weight of gents teachers is 50kg and the average weight of ladies teachers is 40 kg, what is the number of ladies and gents teachers,

20 ladies

30 gents

Step-by-step explanation:

Let :

x = number of ladies

50 - x = number of gents

total weight of the ladies = 40x

total weight of the gents = 50(50 - x) = 2500 - 50x

Average weight : (40x +2500 -  50x) / 50 = 46

cross multiply

2500 - 10x = 2300

combine like terms

2500 - 2300 = 10x

200 = 10x

x = 20 = number of ladies

Number of men = 50 - 20 = 30  

answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.